Brake hydrobooster leak under - fix under 50$

[Goosebumps]

So guys i'm new here and i wanted to share my experince fixing a leaking hydrobooster hope you find it helpful

I'll post a video that was helpful to me fixing the issue plus I'll write my experince and answer your question regardin the fix

Btw this my first time working on the car fixing an issue after watching tons of youtube videos and reading.

After losing power steering fluid and refilling it for more than month i finally noticed that the leak was from the brake hydroboost assembly between the brake master cylinder and hydroboost assembly.

The only special tool needed for the fix is E12 torx socket 3/8" drive and 15mm deep socket 3/8" drive

Before starting deplet the pressure from the system but the car key on off position and press the pedal 5-10 times, disconnect the nigative battery connection.

Disconnet the master cylinder from hydroboost assembly 1 bolt on each side 15mm. Slide it back away from the booster.

You'll find 3 lines connected to the booster unit, you need 15 & 18mm wrench and pliers to remove a clamp from the low pressure hose.

Now moving under the dash driver side behind brake pedal you'll find 4 bolt connecting the booster unit to firewall using 15mm deep socket remove 4 bolts, after that remove the clip thats holding brake pedal switch and the rode arm from the booster unit.

Now you can remove the booster from the fire wall slide it back and up towards you, take it to the bench and start unbolting the torx e12 around, splited apart and change the piston seal you can buy it from amazon the link for the part will be posted below. Screw it back and reverse the previous instruction.

Repair Kit
GM 2771004x Hydro-Boost Repair Kit Seal Leak Repair Universal Kit Rubber Only https://www.amazon.com/dp/B01J2PD1NQ/ref=cm_sw_r_cp_api_CuBOzb83K974M

Hope you find it helpful

 

[bottomline2000]

Yeah my hydro boost sprung a leak out of nowhere. I replaced one of the high pressure hoses only to find it was still leaking. I'm waiting on parts to replace this seal. It was also recommended to replace the figure 8 seal too. I should have replaced this seal before installing the hydro boost, but at least it's a cheap fix. Good part is I flushed the system so I have fresh power steering fluid.. Not looking forward to hanging out in under my dash..

Sent from my SAMSUNG-SM-T377A using Tapatalk

 

[bottomline2000]

Just to follow up on this..finally got the seal replaced..it was a mini nightmare...

Don't--

1. shoot the retaining clip that holds the brake lever and switch to the brake pedal into the dash...you will never find it.. $10 from the stealership..definitely don't shoot the 2nd one into the same abyss..not fun..yes..I did, but went after it like a rabid dog and found it.

2. When u put the hydroboost back together, make sure the cone looking thing slides into place properly..if not when u start you truck the brake pedal will plunge to the floor breaking your brake light switch because there is no clip holding on... $25 from Amazon Prime..same day, but took 2 days..D891a is for non adjustable peels btw..

3. Don't pull hydroboost apart to fix previous assembly error while still mounted to firewall because u are too sore to go back under the dash and do it the right way..hey it worked lol.

Repairs are not always fun so I thought Iit would nice to share my pain..time to take the hoe for a stroll.

Sent from my SAMSUNG-SM-T377A using Tapatalk

 

[Goosebumps]

Just to follow up on this..finally got the seal replaced..it was a mini nightmare...

Don't--

1. shoot the retaining clip that holds the brake lever and switch to the brake pedal into the dash...you will never find it.. $10 from the stealership..definitely don't shoot the 2nd one into the same abyss..not fun..yes..I did, but went after it like a rabid dog and found it.

2. When u put the hydroboost back together, make sure the cone looking thing slides into place properly..if not when u start you truck the brake pedal will plunge to the floor breaking your brake light switch because there is no clip holding on... $25 from Amazon Prime..same day, but took 2 days..D891a is for non adjustable peels btw..

3. Don't pull hydroboost apart to fix previous assembly error while still mounted to firewall because u are too sore to go back under the dash and do it the right way..hey it worked lol.

Repairs are not always fun so I thought Iit would nice to share my pain..time to take the hoe for a stroll.

Sent from my SAMSUNG-SM-T377A using Tapatalk

That was real agony good to hear that you got it all together..

 

[bottomline2000]

That was real agony good to hear that you got it all together..

I will say the brakes work a lot better now so it was worth the pain and suffering. these trucks should have all come factory with hydroboost. Its a night and day difference in stopping power. highly recommend even for stock wheel size, but especially if you are running a big wheel/tire combo.

 

[denalimike]

Hey, I am running into the same issue with the leak between the Hydrobooster and the Master Cylinder. I have been told by Full Service/AC Delco that the parts within the booster are not serviceable and that it will need to be replaced. I can't find the seal anywhere but everywhere I look on YouTube, it shows this fix. (usually in Sierra HD trucks) Any guidance?

 

[Goosebumps]

Hey, I am running into the same issue with the leak between the Hydrobooster and the Master Cylinder. I have been told by Full Service/AC Delco that the parts within the booster are not serviceable and that it will need to be replaced. I can't find the seal anywhere but everywhere I look on YouTube, it shows this fix. (usually in Sierra HD trucks) Any guidance?

If you are sure the power steering fluid is leaking only. And not anything else its possible to do the fix.

Here is a link of the seals i got for my fix

GM 2771004x Hydro-Boost Repair Kit Seal Leak Repair Universal Kit Rubber Only https://www.amazon.com/dp/B01J2PD1NQ/ref=cm_sw_r_wa_api_WHjIzbC0TAHFD

My car is 2006 Tahoe 5.3l

I replaced only one seal and it’s still running good.

Make sure you are equipped with the hydraulic power brake boosters not the vacuum brake boosters.

Hope it helps

 

[bottomline2000]

Hey, I am running into the same issue with the leak between the Hydrobooster and the Master Cylinder. I have been told by Full Service/AC Delco that the parts within the booster are not serviceable and that it will need to be replaced. I can't find the seal anywhere but everywhere I look on YouTube, it shows this fix. (usually in Sierra HD trucks) Any guidance?

Lol, yeah that's not true..look up diyauto on ebay. They sell everything u need. I'm still getting some seepage so I'm not 100% sold its fixed. Hoping it's just residual fluid from taking it apart.



Sent from my SAMSUNG-SM-T377A using Tapatalk

 

[denalimike]

I'm certain as I have to keep filling up the Power Steering fluid once a week or so. I have the one pictured below. Is the Vacuum one just like a circle or wheel shaped one? If so then that's not it. It seems easy enough to replace except for taking off the screws from under the dash. I'm not a small cramped space type of guy.

 

[denalimike]

so, on the link for Amazon, as long as one of them fits, I'm good right? Do I need to worry about the below statement?

Does not include include metal star washer and other metal washers for replacement if you need these components please our other KIT 501 for a complete repair kit!*** This Kit is Sold exclusively by Southwest